Squirrel Nest, Intruder Alarm, and Nissa, Who Shakes the World

Prerequisites

• Squirrel Nest on the battlefield
• Intruder Alarm on the battlefield
• Nissa, Who Shakes the World on the battlefield

Steps

1. Animate the land that has Squirrel Nest attached using Nissa, Who Shakes the World
2. Activate the land with Squirrel Nest attached by tapping it, creating a 1/1 Squirrel creature token
3. When the Squirrel enters, Intruder Alarm triggers, untapping all creatures
4. Repeat from step 2

Results

• Infinite ETB
• Infinite creature tokens
• Infinite mana creatures you control can produce
• Infinite untap of all creatures